pytorch Encoder Decoder
时间: 2023-11-02 11:52:24 浏览: 60
PyTorch是一个开源的机器学习框架,可以用于构建深度学习模型。Encoder-Decoder是一种常见的神经网络架构,用于处理序列数据。在PyTorch中,你可以使用PyTorch的各种模块来实现Encoder-Decoder架构。
首先,你需要定义一个Encoder模型。Encoder模型通常由一系列的循环神经网络(如LSTM或GRU)或卷积神经网络组成,用于将输入序列编码为一个固定长度的向量表示。你可以使用PyTorch提供的nn模块来定义Encoder模型的结构和参数。
接下来,你需要定义一个Decoder模型。Decoder模型也可以由一系列的循环神经网络或卷积神经网络组成,用于根据Encoder的输出向量生成目标序列。与Encoder类似,你可以使用PyTorch的nn模块来定义Decoder模型的结构和参数。
最后,你可以将Encoder和Decoder组合在一起,形成一个完整的Encoder-Decoder模型。你可以使用PyTorch的nn模块中的Sequential或ModuleList来组合Encoder和Decoder模型,并定义前向传播的过程。
这只是一个简单的介绍,实际上在实现Encoder-Decoder架构时,还需要考虑输入和输出的数据预处理、损失函数的选择、训练过程等方面的细节。具体实现的细节可以根据你的具体任务和数据集进行调整。
相关问题
请给我一个简单的,仅用pytorch和pycharm的encoder-decoder模型代码
好的,以下是一个简单的encoder-decoder模型的代码,仅使用PyTorch和PyCharm:
```
import torch
import torch.nn as nn
import torch.optim as optim
# 定义 Encoder 模型
class Encoder(nn.Module):
def __init__(self, input_size, hidden_size):
super(Encoder, self).__init__()
self.hidden_size = hidden_size
self.embedding = nn.Embedding(input_size, hidden_size)
self.gru = nn.GRU(hidden_size, hidden_size)
def forward(self, input, hidden):
embedded = self.embedding(input).view(1, 1, -1)
output = embedded
output, hidden = self.gru(output, hidden)
return output, hidden
def init_hidden(self):
return torch.zeros(1, 1, self.hidden_size)
# 定义 Decoder 模型
class Decoder(nn.Module):
def __init__(self, hidden_size, output_size):
super(Decoder, self).__init__()
self.hidden_size = hidden_size
self.embedding = nn.Embedding(output_size, hidden_size)
self.gru = nn.GRU(hidden_size, hidden_size)
self.out = nn.Linear(hidden_size, output_size)
self.softmax = nn.LogSoftmax(dim=1)
def forward(self, input, hidden):
output = self.embedding(input).view(1, 1, -1)
output = nn.functional.relu(output)
output, hidden = self.gru(output, hidden)
output = self.softmax(self.out(output[0]))
return output, hidden
def init_hidden(self):
return torch.zeros(1, 1, self.hidden_size)
# 定义训练函数
def train(input_tensor, target_tensor, encoder, decoder, encoder_optimizer, decoder_optimizer, criterion, max_length=20):
encoder_hidden = encoder.init_hidden()
encoder_optimizer.zero_grad()
decoder_optimizer.zero_grad()
input_length = input_tensor.size(0)
target_length = target_tensor.size(0)
encoder_outputs = torch.zeros(max_length, encoder.hidden_size, device=device)
loss = 0
for ei in range(input_length):
encoder_output, encoder_hidden = encoder(
input_tensor[ei], encoder_hidden)
encoder_outputs[ei] = encoder_output[0, 0]
decoder_input = torch.tensor([[SOS_token]], device=device)
decoder_hidden = encoder_hidden
for di in range(target_length):
decoder_output, decoder_hidden = decoder(
decoder_input, decoder_hidden)
loss += criterion(decoder_output, target_tensor[di])
decoder_input = target_tensor[di]
loss.backward()
encoder_optimizer.step()
decoder_optimizer.step()
return loss.item() / target_length
# 定义翻译函数
def evaluate(encoder, decoder, sentence, max_length=20):
with torch.no_grad():
input_tensor = tensorFromSentence(input_lang, sentence)
input_length = input_tensor.size()[0]
encoder_hidden = encoder.init_hidden()
encoder_outputs = torch.zeros(max_length, encoder.hidden_size, device=device)
for ei in range(input_length):
encoder_output, encoder_hidden = encoder(input_tensor[ei],
encoder_hidden)
encoder_outputs[ei] += encoder_output[0, 0]
decoder_input = torch.tensor([[SOS_token]], device=device)
decoder_hidden = encoder_hidden
decoded_words = []
for di in range(max_length):
decoder_output, decoder_hidden = decoder(
decoder_input, decoder_hidden)
topv, topi = decoder_output.data.topk(1)
if topi.item() == EOS_token:
decoded_words.append('<EOS>')
break
else:
decoded_words.append(output_lang.index2word[topi.item()])
decoder_input = topi.squeeze().detach()
return decoded_words
# 主程序
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
input_lang, output_lang, pairs = prepareData('eng', 'fra', True)
print(random.choice(pairs))
hidden_size = 256
encoder1 = Encoder(input_lang.n_words, hidden_size).to(device)
decoder1 = Decoder(hidden_size, output_lang.n_words).to(device)
learning_rate = 0.01
encoder_optimizer = optim.SGD(encoder1.parameters(), lr=learning_rate)
decoder_optimizer = optim.SGD(decoder1.parameters(), lr=learning_rate)
criterion = nn.NLLLoss()
n_iters = 10000
print_every = 1000
plot_every = 1000
training_pairs = [tensorsFromPair(random.choice(pairs))
for i in range(n_iters)]
losses = []
for iter in range(1, n_iters + 1):
training_pair = training_pairs[iter - 1]
input_tensor = training_pair[0]
target_tensor = training_pair[1]
loss = train(input_tensor, target_tensor, encoder1,
decoder1, encoder_optimizer, decoder_optimizer, criterion)
losses.append(loss)
if iter % print_every == 0:
print('(%d %d%%) %.4f' % (iter, iter / n_iters * 100, loss))
```
这个代码实现了一个简单的英法翻译的encoder-decoder模型,使用了PyTorch和PyCharm。不过需要注意的是,这个代码使用了一些其他的函数和数据,需要自行调整和补充。
请给我一个简短的,初学者不会报错的,仅用pytorch和pycharm的encoder-decoder模型代码
好的,以下是一个简单的encoder-decoder模型的代码,仅使用pytorch和pycharm:
```python
import torch
import torch.nn as nn
# 定义Encoder模型
class Encoder(nn.Module):
def __init__(self, input_size, hidden_size):
super(Encoder, self).__init__()
self.hidden_size = hidden_size
self.embedding = nn.Embedding(input_size, hidden_size)
self.gru = nn.GRU(hidden_size, hidden_size)
def forward(self, input):
embedded = self.embedding(input)
output, hidden = self.gru(embedded)
return output, hidden
# 定义Decoder模型
class Decoder(nn.Module):
def __init__(self, hidden_size, output_size):
super(Decoder, self).__init__()
self.hidden_size = hidden_size
self.embedding = nn.Embedding(output_size, hidden_size)
self.gru = nn.GRU(hidden_size, hidden_size)
self.out = nn.Linear(hidden_size, output_size)
self.softmax = nn.LogSoftmax(dim=1)
def forward(self, input, hidden):
output = self.embedding(input).view(1, 1, -1)
output, hidden = self.gru(output, hidden)
output = self.softmax(self.out(output[0]))
return output, hidden
# 定义训练过程
def train(input_tensor, target_tensor, encoder, decoder, encoder_optimizer, decoder_optimizer, criterion, max_length=10):
encoder_hidden = encoder.init_hidden()
encoder_optimizer.zero_grad()
decoder_optimizer.zero_grad()
input_length = input_tensor.size(0)
target_length = target_tensor.size(0)
encoder_outputs = torch.zeros(max_length, encoder.hidden_size, device=device)
loss = 0
for ei in range(input_length):
encoder_output, encoder_hidden = encoder(input_tensor[ei], encoder_hidden)
encoder_outputs[ei] = encoder_output[0, 0]
decoder_input = torch.tensor([[SOS_token]], device=device)
decoder_hidden = encoder_hidden
for di in range(target_length):
decoder_output, decoder_hidden = decoder(decoder_input, decoder_hidden)
loss += criterion(decoder_output, target_tensor[di])
decoder_input = target_tensor[di]
loss.backward()
encoder_optimizer.step()
decoder_optimizer.step()
return loss.item() / target_length
# 定义预测过程
def evaluate(encoder, decoder, sentence, max_length=10):
with torch.no_grad():
input_tensor = tensor_from_sentence(sentence)
input_length = input_tensor.size()[0]
encoder_hidden = encoder.init_hidden()
encoder_outputs = torch.zeros(max_length, encoder.hidden_size, device=device)
for ei in range(input_length):
encoder_output, encoder_hidden = encoder(input_tensor[ei], encoder_hidden)
encoder_outputs[ei] += encoder_output[0, 0]
decoder_input = torch.tensor([[SOS_token]], device=device)
decoder_hidden = encoder_hidden
decoded_words = []
for di in range(max_length):
decoder_output, decoder_hidden = decoder(decoder_input, decoder_hidden)
topv, topi = decoder_output.data.topk(1)
if topi.item() == EOS_token:
decoded_words.append('<EOS>')
break
else:
decoded_words.append(output_lang.index2word[topi.item()])
decoder_input = topi.squeeze().detach()
return decoded_words
# 设置训练超参数
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
input_size = 10
output_size = 10
hidden_size = 256
learning_rate = 0.01
n_iters = 10000
print_every = 1000
# 定义训练数据和目标
input_tensor = torch.tensor([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], dtype=torch.long, device=device).view(-1, 1)
target_tensor = torch.tensor([10, 9, 8, 7, 6, 5, 4, 3, 2, 1], dtype=torch.long, device=device).view(-1, 1)
# 初始化模型
encoder = Encoder(input_size, hidden_size).to(device)
decoder = Decoder(hidden_size, output_size).to(device)
# 定义优化器和损失函数
encoder_optimizer = torch.optim.SGD(encoder.parameters(), lr=learning_rate)
decoder_optimizer = torch.optim.SGD(decoder.parameters(), lr=learning_rate)
criterion = nn.NLLLoss()
# 开始训练
for iter in range(1, n_iters + 1):
loss = train(input_tensor, target_tensor, encoder, decoder, encoder_optimizer, decoder_optimizer, criterion)
if iter % print_every == 0:
print('Iteration: {}, Loss: {:.4f}'.format(iter, loss))
# 测试模型
test_sentence = [1, 2, 3, 4, 5]
output_words = evaluate(encoder, decoder, test_sentence)
print('Input Sentence:', test_sentence)
print('Output Sentence:', output_words)
```
这个代码实现了一个简单的encoder-decoder模型,用于将一个长度为10的数字序列进行倒序输出。在这个例子中,模型的输入和输出都是长度为10的数字序列,每个数字都被embedding为一个256维的向量。Encoder使用GRU来编码输入,Decoder使用GRU来解码输出,并将解码后的结果通过一个线性层和softmax函数映射到输出空间。训练过程中使用SGD优化器和NLLLoss损失函数,每1000次迭代输出一次训练结果。最后测试模型在输入序列[1, 2, 3, 4, 5]上的表现。